On Tue, 2006-04-25 at 10:15 +0100, Tim Streater wrote:
At 03:39 21/04/2006, Stephen Sprunk wrote: [..]
OTOH, it's ridiculously easy to get PIv4 space today (512 hosts and two pipes or tunnels), and there's not all that many companies doing it. It's not growing much either. The doors are already wide open for a land rush and >>nobody is taking ARIN up on it. Why does everyone assume it'll happen with v6 if it's not happening with v4, which _is_ useful today?
This is perhaps the most pertinent question to have been asked during this thread and I'm not sure I saw any answer to it. So I'll ask it again. What is the evidence that using v4's PI policy for v6 would lead to a land rush of catastrophic proportions and the routing table becoming huge? All I've seen so far is hand-waving doomsayers.
There is no evidence, but it might just happen ;) Maybe not today, but maybe in a couple of years. IPv6 is intended to be there for the coming decades, not for tomorrow.
Remember that to get PI space at all you have to know what you are doing, and you have to justify the usage. And the process takes a certain time. All of these would tend to discourage the casual enquirer.
This is indeed the only limit for both IPv6 PA and the new to be coming PI space: you need to know what you are doing. Thus upto the time that somebody writes up a "HOWTO: Multihoming at home" document it should not cause much issues. That said, when/if a landrush would break out, people are still in control of their own routers and it will become very easy to start filtering certain small prefixes. This happened also in IPv4 (try announcing a /28 or so ;). At that point, people who have the cash can keep on doing it that way, other folks will have to resort to different methods like shim6/hip/sctp and a number of other proposals. In the end one will still need "PI" space at most sites anyway. As it is the sole method of making sure that one can stick IP addresses in certain important places like firewall rules and DNS without ever having to think about it again or having to remember that you stuck them there. This is where the above methods come in, they will make the packet, while traveling over the internet be the upstreams src/dst, while being "PI" on the edges. This solves all the issues at hand. For the time being though people can happily use IPv6 PI space in the way they are 'used' to in IPv4. This gives enough time for the new methods to become crystal clear and cover all the known problemspaces so that end-sites can use them happily ever after. Greets, Jeroen